Machine tool including fluid operated feeding devices



Jan. 12, 1937. E. J. KINGSBURY MACHINE TOOL INCLUDING FLUID OPERATEDFEEDING DEVICES Filed Jan. 6, 1934 3 Sheets-Sheet l INVENTOR Edwardi-AUORNEYS.

..... i BY E w R filmill lll-llll R *1 Jan. 12, 1937.

E. .J. KINGSBURY MACHINE TOOL INCLUDING FLUID OPERATED FEEDING DEVICESFiled Jan. 6, 1934 5 Sheets-Sheet 2 everse'n Ll L1 Biz/m1 ATrbRNEYs.

Patented Jan. 12, 1937 UNITED STATES- PATENT OFFICE MACHINE TOOLINCLUDING FLUID OPERATED FEEDING DEVICES 19 Claims.

The present invention relates to improvements in machine tools havingfluid operated feeding devices, and is more particularly directed to theprovision of a fluid operated feeding system including a pump and meansfor operating the pump in accordance with the requirements of thefeeding system.

One of the features of the present invention is the provision of amachine tool in which a moving structure is fed by hydraulic means, thefluid pressure being produced by a pump which is controlled in itsoperation by the movement of the structure being fed.

Another feature of the present invention is r the provision of a machinetool having a plu rality of separately movable members each'providedwith fluid operated feeding means, and a common source for producing thefluid movement which actuates the moving structures, this common sourcebeing controlled by the movements of the moving structure.

A further feature of the present invention is the provision of a machinetool in which is provided a moving structure and a fluid operated meansfor feeding the same, the feeding in one direction being accomplished byfluid under pressure being delivered to the fluid operated means, andthe feeding in the reverse direction being accomplished by withdrawal offluid from the fluid operated means, the delivery and withdrawal of thefluid being accomplished by a 'pump system under control of themovements of the movable structure and of the pump itself.

Other features of the present invention will appear in the course ofthe'following specification and claims, in conjunction with theaccompanying drawings which show an illustrative form of practicing theinvention, and in which a hydraulic system is employed for the fluiddelivery, withdrawing and operating system.

In these drawings:

Figure 1 is a diagrammatic view, with illustrative parts in section,showing the assembly of a machine tool of the present nature, in which apair of tool units having separate movable tool heads are provided inconjunction with a common pump for moving the fluid.

Figure 2 is a view, on a larger scale, showing one of the tool units ina different operated position.

Figure 3 is a circuit diagram. H 7

Figures 3a and 3b show similar diagrams with the parts in positions forforward and reverse movement.

- In the drawings, two tool units Ai, A2 are.

shown as being identical in design, and are illustrated as having toolheads which are fed toward one another during the operation of the twotool units. A common pump system B is provided for deliyering fluid tothe units and withdrawing it therefrom, in multiple.

The pump system comprises in the illustrative form a reversible electricmotor In connected to which serves constantly to press the shaft l5ftoward the left so that the clutch ll establishes a driving relationwith shaft ll.

The worm I6 is in mesh with a worm wheel 20 on a shaft 21 having apinion 22 thereon meshing with a rack 23 provided on the pump piston rod24 which is guided in the frame l3 and is provided with a' piston 25.within the cylinder structure 26 carried by the frame l3. The rightwardmovement of piston 25 causes the fluid within the cylinder 26 to beejected through the common conduit 30 to a manifold conduit 3| which isjoined to both tool units Al and A2.

These two tool units are illustrated as identical in construction. Eachof them has a fixed frame portion 35 which may be secured to any desiredsupport and in the proper location opposite the fixture or other device(not shown) which is provided to support the work to be operated upon.Each frame 35 supports the individual motor 36 which is connected by abelt 31 to the pulley 38 on a 'splined sleeve 39 journaled in the frame35 and in driving relationship with the tool driving shaft 40 whichextends through a bearing piece M- likewise guided in frame 35 and isconnected to the movable tool head 42. These tool heads are illustratedas containing gears 43 by which the tool downward extension 49 whichreceives a valve rod 50 which is threaded at both its ends and isprovided with a reduced portion 5| within the 7 frame 35. Lock nuts 52clamp the valve rod 50 'frame 35 to determine-the position of maximumwithdrawal of the tool head 42 with respect to the frame 35 and thework. A split sleeve 56 is likewise threaded to the valve rod 50, at theopposite end thereof, and may be clamped at its adjusted position by theclamping screw 51;

and operates by engagement with the frame 35 to limit the forwardfeeding movement of the tool head (in position of Fig. 2).

-The pump system fr'ame I3 is provided with walls providing a sump 60for oil or like liquid, and a supply pipe 6| establishes communicationof the cylinder 26 with the chin this swim, a check valve 62 beingprovided to prevent direct return movement of the liquid from thecylinder to the sump.

A limit switch 10 having a rocker arm 1| is operated by the pump pistonrod 24 when the latter reaches its extreme leftward movement (Fig. 1)whereby to -open a control circuit.

Limit switches 12 are'provided on each of the tool units AI and A2 andhave rocker arms 13 which are engaged by the enlarged portions of thesplit sleeves 56 shortly before these sleeves encounter thecorresponding frames 35, wherebyto close the switches 12.

Within each of the frames 35 is provided a passage in extension of themanifold conduit 3| and communicating with the hole in which the valverod 50 moves, so that when the reduced portion 5| thereof is oDpOsitethe passage 80 (Fig. 1) the fluid may flow further through a passage 8|into the cylinder space 41 and cause a movement of the piston 46 towardthe left for tool unit AI. piston 46 enforces a leftward movement of thecorresponding tool head 42 and therewith ofthe corresponding valve rod50, so that ultimately the reduced portion 5| passes from the passages80 and 8|, and this direct flow of fluid medium is shut off. A primary'by-pass conduit 82 leads from passage 80 and opens into the cylinderspace 41 near the top thereof, and

has therein anexternally adjusted metering valve 83 which controls theflow of fluid under pressure from the manifold conduit 3| into thecylinder space 41, to restrict the rate of movement of the piston 46undersuch condition.

When the pressure in'manifold conduit 3| :falls below the pressure .incylinder space 41 tothe right of piston 46 in tool AI, fluid tends tomove iii the opposite direction from the cylinder toward the manifoldconduit, and is then permitted to move through passage 84 and checkvalve 85 to conduit 82, so that a rapid return feeding movement-isattained. The return movement of the tool head 42 is assisted by theoperation of the chain passing over sprocket 9| and connected to acounter-weight 92; the sprocket 9| being journaled on a bracket 93 offrame 35 At the highest point of conduit 82 is provided a lateralconduit 95 leading to an external pet- This leftward movement of thecock 96; so that air may be evacuated from the system.

In the circuit diagram of Figure 3, the reversing motor I0 isillustrated as of three-phase type. The three-phase conductors I00 arealternately and selectively connected to the motor I0 by the operationof the reverse relay R and the forward relay F, having the respectiveenergiz- 7 ingcoils IOI and I02. A pilot switch I03 is employed to startthe system from the initial position shown in Figure 1. Upon closing thepilot switch I03, current flows from one phase conductor I00 byconductors I04 and I05 and the switch conductor I06. through the switchI03. by conductors I01 and I08 tothe coil I02 and back by conductor I09to another phase conductor I00. The relay F is energized and its contactbridges are raised to connect the phase conductors I00 through branchphase conductors I00a'to the reversing .motor I0 which begins to turn ina forward direction. This condition is shown in Fig. 3a, whichalsoindicates the closed position of the pilot switch I03 for initiatingsuch movement, The closing of the lower bridge of relay F alsoestablishes a maintaining circuit from a phase conductor I00 byconductor IIO, the lowered bottom bridge of openrelay R, conductor III.the raised and closed bottom bridge of relay F, conductors H2 and I08,through coil I02 and back by conductor I09 to a phase conductor I00.

In this position of the electrical parts, the motor I0 drives shaft II,and clutch I4 is held closed by spring I9 so that worm I6 turns th wormwheel 20 and thus the pinion 22 and rack 23 cause the piston 25 to movetoward the right in Figure 1 and force fluid through conduits 30 and3I-t0' the'tool units AI and A2. In each unit, the fluid flows past thereduced portion 5| of the valve rod 50 and directly enters the cylinderspace 41 through passage 8| and the tool heads 42 are pushed away fromthe frames 35 at a rapid rate in a forward feeding movement. These ratesmay not be identical. Ultimately, the valve rods 50withdraw the reducedportions 5| from between passages 80 and 8|, and thereafter only a slowfeeding movement can be.produced owing to the operation of the 'on theworm wheel 20 and worm I6. Ultimately,

this slow forward feeding movement of the individual unit is stopped bythe engagement of the split sleeve 56 with the frame 35, andsimultaneously the limit switch 12 of the unit is closed. The tool head42 is thus brought to al standstill at a position which may be closelyregulated by setting the split sleeve 56, and thereafter no furtherliquid is received by the cylinder space 41 and a high back pressurebuilds up in conduits 3| and 30 and thus in the cylinder 26. Accordingto the setting of the adjusting screw I 9a, the pressure between theworm wheel 20 and the worm I6 attains such a value that the worm I6 isforced toward the right against the spring I9 and thus releasing theclutch I4. The motor I0 is thus substantially disconnected from thepiston 25, but a succeeding movement of the piston 25 will returning inthe forward direction, and liquid is I being accepted by the tool units.

The tool unit has now attained the position shown in Figure 2.

The closing of the limit switches 12 has estabforward relay F isdeenergized, and forward relay F drops and breaks the connection betweenphase conductors I00 and IBM. The lifting of reversing relay Rimmediately closes circuits from the phase conductors I00 to the motorfeeding phase conductors lllllb, but with reversing connection to two ofthe phase conductors, so that the motor 10 is now energized in thereverse direction, and is thus brought into motion in the oppositedirection This condition is illustrated in Fig. 3b with the unit limitswitches 12 and the pump limit switch Ill closed; and the motor Illturning in the reverse direction from that illustrated in Fig. 3a.. Amaintaining circuit is also established from a phase conductor Hill byconductor I04, pump limit switch 10, conductor III, thenext-to-the-bottom bridge of relay R, and conductors H8 and M to thecoil 10!.

T The reverse movement of the motor l0 causes the worm Hi to remainengaged with the worm wheel and thus to cause'the piston rod 24 to bemoved toward the left in Figure 1, so that piston 25 sucks the liquidfrom the two tool units. At first; this suction occurs: past themetering valve 83 and the conduit 82 of each unit, along with a flowpast the check valve 85 thereof, so that the tool head 42 is drawnrapidly back toward the withdrawn position. The valve rod 50 is movedwith the'tool head and ultimately the reduced portion 5| again comesbetween the passages 80 and 8|, and a direct flow back "from thecylinder space 41 through conduits 3| and to cylinder 26 occurs.Finally, the spacing member 53 encounters the frame and brings the toolhead to a standstill in its I It will be noted that the tool units Aland A2 may be mounted at any desired position and relation to oneanother by having the conduits 30 and Si of extensible or flexiblenature, so that the tool units may be assembled upon a standardcontaining the pump system B.

If at any time air tends to accumulate in the conduit and passagesystems, the petcocks 96 may be opened while the piston 25 is movingtoward the right (Fig. l), and then the air is ejected from thecollection conduit 95. When oil appears at the petcocks, they areclosed. During the succeeding leftward movement of the piston 25, itscomplete movement is permitted by the-sucking of replacement liquid fromsump through P p 6 past the check valve 62..

It' is obvious that the invention is not limited to the illustrativeexample of practice shown,

but that it may be employed within many ways of the scope of theappended claims.

Having thus described the invention, what I claim as new and desire tosecure by Letters Patent, is:

1. A machine tool including a plurality of separate tool units eachhaving a tool structure which is fed forward for cutting and-fedbackward for withdrawal and each including fluidpressure-operated meansfor feeding, a reversible fluid-pressure pump, conduit means connectingsaid pump with all the fluid-pressure-operated means, a reversiblesource of power, and transmission means including a slip clutchconnecting said source and said pump so that said source andtransmission means operate through the slip clutch to determine themaximum pressure in said conduit means.

2. A machine tool including a plurality of separate tool units eachhaving a tool structureoperated by said tool units for reversing saidand fed backward for withdrawal and including 1 a single-action cylinderand piston for feeding said structure, a single-action pump including acylinder and piston, a conduit connecting said cylinders, a valve movedwith said tool structure to close said conduit, a by-pass conduit aroundsaid valve and a metering valve for controlling the flow of fluidtherethrough, a reversible source of power connected to said pump tomove the same, limit devices on said units operated at the end of theforward feeding thereof, limit devices on the pump operated at the endof the withdrawal movement thereof, and devices controlled by said limitdevices for reversing and stopping said source of power.

4. A machine tool as in claim 3, in which the. source is connected tothe pump through a connection which slips at a predetermined maximumpressure in said conduit, and a further conduit is provided forcommunication from said connecting conduit to said feeding cylinder, anda. check valve in said further conduit for preventing fiow therethroughto said cylinder and permitting such flow from the cylinder whereby arapid withdrawal feeding movement is attained.

4 and a single conduit connecting said pump with all said feeding meansso that the movement of fluid from said pump through said conduit to thefeeding means will produce a forward movement of all said spindles and areturn movement of the same time after all said units have completedtheir advancing movement.

6. A machine tool including a plurality of separate tool units eachhaving a tool spindle and means for driving the same, fluid-operatedfeeding means for advancing and withdrawing the spindle, and individualmeans on each unit for restricting the flow of fluid whereby to producea slow movement; a common mechanismfor moving fluid connected to allsaid feeding means and including a pump, a reversible source of power,and a transmission connecting said pump .and source and including aconnection which slips when the pump-requires more than a. pre:

in said conduit attains a predetermined maxi-- determined amount ofenergy for its continued movement; and control means interconnectingsaid units and common mechanism for reversing said source-at the end ofthe advancing: movement of all said spindles.

7. A machine tool including a tool unit having a fluid-operatedmotivemeans for feeding the tool forward and back, a pump and a singleconduit from said pump to said motive means, a reversible source ofpower, means for reversing said source at the completion of the forwardmovement, and a transmission connecting said source and pump to operatethe latter and including a clutch which slips when more than apredetermined maximum pressure is transmitted thereto during the forwardfeeding, and means for adjusting the clutch with respect to said maximumpressure transmitted thereby, whereby to regulate the feeding pressureexisting in said motive means.

8. A machine tool including a tool unit having a fluid-operated motivemeans for feeding the tool forward and back, a pump and a conduit fromsaid pump to said motive means, a reversible source of power, means theunit for varying the rate of consumption of fluid by said motive means,a transmission connecting said source and pump to operate the latter andincluding a clutch which slips when the pressure in said conduit attainsa predetermined maximum, and a control device actuated by the unit forconnecting the source for reversed energization after a predeterminedforward movement of the 9. A machine tool including a tool unit,fiuidoperated motive means for producing relative" feeding movements ofthe tool and work, a pump and a conduit from said pump to said motivemeans, a reversible source of power, means in the unit for varying therate of consumption of fluid by said motive mcfims, a transmissionconnecting said source and pump to operate the latter and including aclutch'which slips when the pressure mum, and a control device actuatedby the pump after a predetermined movement thereof in one direction forterminating the pump movement in said direction.

10. In a machine tool, fixed and movable structures, piston and cylinderfeeding means connected to said structures for producing relaactuated atthe end of the restricted relative movement of said structures in onedirection for producing a reversal of the drive of said pump from saidsource, slip means included in said transmission and operative at apredetermined pressure in said conduit means to determine the actuationof said pump for moving said structures relatively in said onedirection, and means operated by the movable structure for producing areversal of the pump movement after a predetermined travel of saidmovable structure and thereby effecting a relative movement of saidstructures in the other direction.

11. In a machine tool, fixed and movable structures, single-actionpiston and cylinder feeding means connected to said structures forproducing relative movements thereof, a pump including single-actionpiston and cylinder means, a single conduit connecting said cylinder;means and providing therewith a substantially liquid-tight system inwhich liquid is moved back and forth to and from said pump and feedingpump piston is operating to force liquid toward said feeding means, andcontrol devices actuated at the end of the restricted relative movementof said structures caused by the forcing of liquid into said feedingmeans and operating to determine thereafter a reversed movement of saidpump.

12. In a machine tool,- fixed and movable structures,fluid-pressure-operated means for moving said movable structure in onedirection, a pump for delivering fluid to said fluid-operated meansunder pressure to effect said movement, a reversible motor, meansincluding a slip clutch connecting said motor and pump, meanscontrolling the clutch to effect a disconnection of the motor and pumpupon a predetermined maximum pressure in the latter, first meansactuated upon a predetermined movement of the movable structure in saidone direction for re lversing the motor and effecting movement of'versible motor, means including a slip clutch.

connecting said motor and pump, means controlling the clutch to efiect adisconnection of the ,motor and pump upon a predetermined maximumpressure in the latter, first means actuated upon a. predeterminedmovement of the movable structure in said one direction for reversingthe motor and efiecting movement of said movable structure in the otherdirection,

and second means connected with said first means and actuated upon apredetermined movement of the pump for terminating the movement of saidmovable structure in said other direction.

14. A machine tool including a plurality of .during forward movement forfeeding all said spindles forward and during reverse movement forreturning all said spindles, devices interconnecting all said units andpower driven means for producing a reversal of said power driven meanswhen each spindle has attained its extreme forward position, and devicescooperating with said interconnecting devices and actuated by the powerdriven means at a limit of reverse movement thereof for terminating suchreverse movement. r

15. A machine tool including a plurality of separate. tool units eachhaving a tool spindle which is moved forward for cutting and backwardfor withdrawal and each including yielding means for moving the spindle,a single reversible power means connected to all said yielding means formoving the same and including clutch devices for slipping when thecombined resistance of all said spindles exceeds a predetermined value,control devices on said units, and means interconnecting the same withsaid power means for reversing the latter when all said units haveattained a forward position predetermined for each said unit and therebyeffect a simultaneous backward movement of all said spindles.

16. A machine tool including a plurality of separate tool units eachhaving a tool spindle which is moved forward for cutting and backwardfor withdrawal and each including yielding means for moving the spindle,a single power-driven means connected to all said yielding means andoperative therethrough during its movement in one direction to move allsaid spindles forwardly and during its movement in the oppositedirection to move all said spindles backwardly, a reversible source ofpower for said power-driven means, control devices on said units andmeans interconnecting the same with said power-driven means forreversing the said source of power when all said units have attained aforward position predetermined for each said unit and thereby effect asimultaneous backward movement of all said spindles and operating forholding the spindles thereafter in withdrawn position for terminatingthe reverse movement'after a predetermined movement of the power-drivenmeans.

17. A machine tool including a plurality of separate tool units eachhaving a tool structure which is fed forward for cutting and fedbackward for withdrawal and each including relatively reciprocablepiston and cylinder means for feeding, a pump including relativelyreciprocable piston-and cylinder means, conduit means establishingcommunication between all said cylinder means so that relative movementof the pump piston in one direction can produce simultaneous forwardmovement of all said tool structures and movement of the pump piston inthe opposite direction can produce simultaneous backward movement of allsaid tool structures, a. reversible source of power and transmissionmeans including a slip clutch connected to said pump, said slip. clutchoperating to determine the maximum pressure in said conduit means,

and devices controlled by said units for reversing said source whenallsaid units have attained an individually predetermined forwardposition.

18; In a machine tool including a plurality of separate tool units eachhaving a tool structure which is fed forward for cutting and fedbackward for withdrawal and each includinga fluidpressure-operated meansfor feeding the tool structure and means for regulating the supply offluid to said fiuid-pressure-operated means, a

pump, single conduit means connecting the pump and all saidfluid-pressure-operated means and including said regulating means, meansfor driving said pump, and control devices for reversing said drivingmeans and operating to move the pump alternately for a predetermineddistance in one direction for feeding the tool structures forwardsimultaneously and then for substantially the same distance in theopposite direction for withdrawing the tool structures simultaneously,said slip clutch being effective to determine the maximum pressure inthe conduit means so that the maximum rate of advancement ifi each unitis determined by the tool resistance and the controlling action of itssaid regulating means at said maximum pres: sure.

19. A machine tool including a plurality of separate tool units eachhaving a tool structure which ismoved forward for cutting and movedbackward for withdrawal and each including fiuid-pressure-operated meansfor feeding and each including positive means for mechanically limitingthe forward and backward movements thereof and means for regulating thesupply of fluid to said fiuid-pressure-operated means and for permittinga substantially free return of fluid from said fluid-pressure-operatedmeans during the backward-movement thereof, a re: versiblefluid-pressure pump, a single conduit connecting said pump with all thefluid-pressure-operated means, a reversible source of power, andtransmission means including a slip clutchconnecting said source andsaid pump so that the pump alternately delivers fluid to and withdrawsit from said conduit according tothe direction of movement of saidsource, and so that said slip clutch operates to limit the maximumpressure occurring in the single conduit while fluid is being'fdeliveredthereto for the forward movement of all the tool structures.

EDWARD JOSLIN mNGSBURY.

